1. Field of the Invention
The invention relates to a gasoline vapor recycling system for gasoline tank, particularly for balancing vapor pressure in a gasoline tank where gasoline vapor increases excessively as oil is discharged from a gasoline tanker to gasoline tank and processing discharged gasoline vapor through a discharge processing apparatus to purify the vapor and separate liquid gasoline to reduce pollution and hazard resulting from directly discharging the gasoline vapor and improve energy reclamation and utilization.
2. Description of the Prior Art
Gasoline is a volatile liquid fuel. The volatile gasoline vapor not only easily burns and causes the risk of fire, also is hazardous to human body and environment. Hence to process the dispersed gasoline vapor is an important safety issue on gasoline storage sites such as vapor stations. The present gasoline vapor process method at the vapor stations generally can be divided in two stages depends on gasoline vapor generation types. The first stage mainly targets the gasoline vapor in the closed gasoline tank underground. The gasoline tank generally is filled with substantial saturated gasoline vapor due to change of environmental temperature or inflow of a great amount of gasoline vapor during the gasoline tanker unloads the gasoline. As a result, the pressure in the gasoline tank is unbalanced. Hence a ventilation pipe usually is provided to communicate the gasoline tank with the ambience to discharge the gasoline vapor to balance the pressure in the tank. But such an approach directly discharges the gasoline vapor without processing into the atmosphere. It causes a great hazard to the environment. The second stage is to reclaim the gasoline vapor escaped from the gasoline nozzle while the gasoline is injected into the vehicles by a gasoline vapor recycling means mounted on the gasoline nozzle. However, the gasoline vapor reclaimed into the gasoline tank also encounters the problem of the first stage previously discussed. A breathing pipe has to be used to release the pressure and pollution and safety issues still exist.
At present gasoline delivery and distribution usually is done by transporting the gasoline through gasoline tankers from the refinery to gasoline tanks in gasoline depots located on different locations. During the process of unloading the gasoline from the gasoline tanker into the gasoline tank, a great amount of gasoline vapor is generated and evaporates from the gasoline tank. Some gasoline tankers have gasoline vapor recycling apparatus to reclaim the gasoline vapor through another piping into the gasoline tanker. The reclaimed gasoline vapor is transported to the refinery or gasoline storage to be recycled to liquid type gasoline again through condensation, adsorption by active carbon, film separation or the like. Although the aforesaid gasoline vapor recycling method on the gasoline tanker can reduce gasoline vapor escape and air pollution, the recycled gasoline vapor is transformed to gasoline and sold to the refinery. It is a great loss to the buyers such as the vapor stations.